Automatic transmission



Aug- 26, l941-A w. Q. wATTERsoN 2,253,877

By I A orney Patented Aug. 26, 1941 UNITED STATES PATENT OFFICE y 2,253,311 sommano :raaNsmssroN Wilfred Quayle Watterson. South Pasadena, alif., assignor to Kenneth Lynn Frazier, San

C Gabriel, Calif.

Application January 24. 1941,l serial No. 315,35: 4 calms. (cl. isz-so) transmitting it smoothly in correct proportion to the engine speed and load.

Other objects and advantages of the invention will become apparent to the reader of the followingdescription.

Inthe drawings:

Figure 1 represents a longitudinal sectional view through the transmission. Y

Figure4 2 is a transverse vertical sectional view taken substantially on t e line 2--2 of Figure 1.

Figure 3 i's a transver vertical sectional view the outer end of a corresponding pitman 2l. y The inner ends of these pitmans 2l are provided with laterally flanged heads 22 and rings 23 are taken substantially on the line 3-3 of Figure 1.

A pitmans.

Figure 8 is a perspective view of one of the Referring to the drawings wherein like Lnumerals designate like parts, it can be seen that 7 is a perspective view of one of the provided on the crank and around the flanges of the heads 22 to prevent displacement of the heads.

At each of the cylinder heads I6 and interrupting the passageway l1 thereof, is a rotary valve 24. Each of these rotary valves has suitable bearing means 25 and is provided with a stub shaft 26 extending from one end thereof and through one side of the head I6 in a forward direction. These rotary valves are located in bores of the cylinder head I6 and are held in place by nuts 21.

As can be seen in Figure 1, the removable plate 6 of the transmission housing has a boss 28 at its forwardside, containing a bearing assembly 28 through whichthe driving shaft 5 extends. This boss 23 has a forwardly projecting barrel 30 terminating in a packing gland 3l receiving the driving shaft 5. 1

'I'he crank I2 is mounted at the rear end of the driving shaft I and within the transmission housing. A pump impeller generally referred to bynumeral 32 is provided in the transmission housing just forwardly of the crank lI2 and this` consists of a hub 33 suitably secured to the drivnumeral l denotes a drive shaft which canbe suitably connected with the driving motor. A The on includes a shell consisting of a removable front wall 6, a rear wall 1 and a circumferential wall 3. The central portion of the rear wall 1 has a boss formation 3 containing a bearing assembly ll for the stub shaft extension Il of a crank l2. This boss formation 3 has threaded openings i3 therein for receiving machine screws employed in attaching a driven shaft Il. w

Carried by the inside of the rear wall 1 and the circumferential wall 3 are radially disposed vcylinders Il, each of which has a head I3 through which an L-shaped passageway l1 extends oommunicating the interior of the cylinder Il withthe interior of the transmission housing. In each of the cylinders II is a piston inthe samehavlngabifurcatedskirt I3 aperturedto receive a wrist pin 2l. this pin extending ing shaft 5 and provided with a plurality of radially disposedblades 3l. A pair of annular side walls 35 are secured to opposite side edges of the blades 3l and have their inner edges spaced from the hub 33. As the interior of the transmission contains a considerable volume of oil or other suitable duid, fluid caught within the connes of the blades 34 as the impeller 32 is rotating, is thrown `outwardly and into the substantially S-shaped eways 33 of the control. 'I'he 8-shaped passageways are formed in a fixed annulus 31 which circumscribes the im peller 32. Deilectors 33 extend into the passageways 33 for a purpose which will be hereinafter more fully set forth.

Operating arms 33 are mounted across the passageways 33 and each is provided with a spring l0 which serves to swing the arm 33 to abut its corresponding dellector 33. Each of these arms 33 is suitably keyed or otherwise secured to its corresponding rotary valve stub 23.

As can be seen in Figure 5 each cylinder head I3 has a bracket 3l mounted atthe side thereof and through this is feedable a pin I2. 'Ihe pin l2 has a threaded portionV I3 which extends through a nut or internally threaded member 43.

through 'lhisthreadsdportionextendsthroughthe rear side 1 of the transmission housing. Also mounted on the bracket 4| is a triangular-shaped plate 45 against which the pin 42 is movable to swing the plate 45. As the corresponding spring 40 is attached to the forwardmost portion of the plate 45, in which driving of the pin 42 will result in the swinging of the plate 45 to increase the tension of said spring.

The speed ratios between the driving shaft and the drivenv shaft are infinite. The speed at which the direct ratio is reached is controlled by the speed of the driven shaft. This speed is variable and can be adjusted to suit any particular condition. However, adjustments cannot be made while the device is in motion.

The following describes the cycle of events taking place in the unit when power or torque is applied to the driving shaft 5: As previously stated, the rotary valves 24 are spring held, and each one is adjusted so that the tension maintained will automatically change the speed at which the 1 to 1 ratio will become effective. Also, the engine crankshaft i2 and the driving shaft 5 of the unit are directly connected to each other and therefore rotate at the same number of R. P. M. When the unit is at rest,the hydraulically balanced rotary valves are held in their wide open position by springs 40 acting on the control arms 39. In this position, the hydraulic fluid is permitted to pass back and forth from the piston heads i6 to the main fluid chamber without restriction.

lThe engine is started and allowed-to run at idling speed. Hydraulic fluidA in the unit is now put in circulation by the pump impeller 32 and at the same time the pistons are free to move in their respective cylinders, because at low engine speed, the pump impeller does not impart enough kinetic energy to the fluid to operate the control arms.P Since no restriction is placed on the hydraulic fluid above the pistons, no torque is transmitted to the driven side of the unit, and the so-7 called neutral position is maintained.

As engine speed is increased, the uid ,circulated by the pump impeller strikes the control armswith enough force to cause them to move outwardly toward the rim of the case and in doing so, the rotary valves are partially closed. This partial closing causes an impediment in the ow of the iluid between the cylinders and the uid chamber. This restriction in turn causes the cylinder blocks,` which are directly connected to the driven shaft and free to rotate around the,

driving shaft, to be moved ahead in the same direction as the driving shaft. The speed at which the driven shaft is rotated depends upon three factors: namely, engine R. P. M., load on driven shaft, and speed of driven shaft.

As the speed of the engine increases, vthe ro- Vtary valves continue to close, thereby causing the flow of fluid between the cylinders and the main fluid chamber to become more restricted, .which in turn causes the speed of the driven shaft I4 to increase.

'I'he driven shaft with its attached cylinder blocks and control arms rotate as a unit, and as its speed increases, the relative speed between the pump impeller and the control arms de' creases with the attendant falling oi of kinetic energy transmitted by the circulating fluid to the control arms. However, when this speed is reached, centrifugal force acting on the weighted control arms is now vgreat enough to force them outwardly to the limit of their are, and when thislimit is reached, the rotary valves are completely closed preventing the pistons from movgrades where the motor is used asv a brake, be`

cause when the vehicle reaches the predetermined speed setting of the control arms, the unit automatically locks itself in direct drive. Also it is impossible to make a rough start because the unit transmits the power steadily and evenly in proportion to the load.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from .the spirit and scope Vof the invention as claimed hereinafter.

Having described the invention, claimed as new is: v

l. A transmission comprising a housing, a driven shaft extending from the housing, a drive shaft extending into the housing and provided what is with a crank at the housing end thereof, cy1in,

' `the interior of the housing, rotary valves traversing the passageways, a fluid impeller carried by the drive shaft and at the inside of the hous-- ing, a control structure surrounding the impeller and having a plurality of passageways extending outwardly therethrough and control arms in the passageways of the control structure operatively connected with the valves. f

2. A transmission comprising a housing, a driven shaft extending from the housing, a drive shaft extending into the housing and provided with a crank at the housing end thereof, cylinders carried by the housing, pistons operative in the cylinders, pitmans connected to the pistons andvbeing operatively associated with the crank,Y

passageways in the heads lof the cylinders communicating the interiors of the cylinders with the interior of the housing, rotary valves traversing the passageways, a iluid impeller carried by the drive shaft and at the inside of the housing, a control structure surrounding the impeller and having a plurality of passageways extending outwardly therethrough and control arms in the passageways of the control structure operatively connected with the valves, and fluid deilectors in the passageways of the control structure.

3. A transmission comprising a housing, a driven shaft ,extending from the housing, a drive shaft extending into the housing and provided with a crank at the housing end thereof, cylinders carried by the housing, pistons operative in the cylinders, pitmans connected to the pistons and being operatively associated with the crank, passageways in the heads of the cylinders communicating the interiors of the cylinders with the interior of the housing, rotary valves traversing the passageways, a fluid impeller carried by the drive shaft and at the inside of the housing, a control structure surrounding the impeller and having a plurality of passageways extending outwardly therethrough and control arms in the passageways of the control structure Cil ways, a fluid impeller carried by the drive shaft and at the inside of the housing, a control struc.- ture surrounding the impeller and having a plurality of passageways extending outwardly therethrough and control arms in the passageways of the control structure operatively connected with the valves, and spring tensioning means for the arms and means for adjusting the tension of the spring means.

WILFRED QUAYLE WA'ITERSON. 

